149 . 
-rS.A. NAT., VOL. XIV. 
August 3 1st, 1933. By Bernard C. Cotton and F. K. Godfrey. 
This girdle is removed from the apex a distance about equal to 
the diameter of the latter. There is no thickening of the shell 
wall toward the aperture, and no appearance of striae under 
considerable magnification. 
C. angustior V erco 1911. PI. 1, figs. 5, 5a and Sb. “The 
Narrower Cadulus.” Thin, slightly curved, chiefly in the poster- 
ior half, cylindrical, very gradually increasing from behind and 
very slightly narrowed at the front, scarcely compressed laterally; 
fractured at posterior end at right angles to the curve, and with 
a small triangular spine, 1 mm. long, projecting backwards from 
the convex side; anterior end open, sloping obliquely forwards 
from the convex side; margins simple, smooth; shell smooth, 
diaphanous; a transverse milky line present or absent near the 
front and sometimes near the posterior end. Length 4.6, breadth 
..6 mm., 26 fathoms 18 miles south-east of Newland Head, South 
Australia (type localit)'), also Cape Borda 62 fathoms. Also 
Western Australia — Hopetoun. King George Sound, Geographe 
Bay, 12-35 fathoms. Yvomif aduhis acxtminatus Tate, it is nar- 
rower and more cylindrical, with less bulging about the middle. 
-Dredged b)^ Verco; with the type, were many specimens which 
appear to show the three progressive stages of growth — first 
as a Dentalhim-W^Q shell, \vhich becomes constricted when it 
reaches a certain age, then begins to form the proper Caduhis 
shell, from which it subsequently breaks off, leaving the tiny pro- 
jecting spine beyond the line of fracture. 
C. laevis Brazier 1877 {Dentalium) (not D. laeve Schlo- 
theim). Strongly arched, half-moon shaped; light amber, some- 
times white, glossy, smooth; basal margin pinched in about 
four millimetres long, forming somewhat like a shoulder, then 
•slightly varicose, from that to the apex regularly tapering; apex 
with a minute perforation, entire. Length 28, diam. base at 
shouder 2, below I mm. of Neptune Islands, 62-104 fath- 
oms. (Type locality — Princess Charlotte Bay, Northeast Aus- 
tralia, 13 fathoms, sandy mud). I’he lower part of this shell 
resembles the spines of sea-urchins. The greater part of the 
specimens are encrusted over witj^a fine coating of coral-like 
substance (Brazier), South Australian specimens seem closely 
related to this species. 
C. occiduud \'erco 1911. Ph 1, fig. 7. “The Western 
Cadulus.” Rather solid; ventral curve nearly uniformlv slightly 
convex; dorsal side nearly straight in the anterior fourth, slightly 
convex in the next quarter, and slightly concave in the hinder 
half; cut off perpendicularly to the axis behind, rather obliquelv 
in front, where the slope is backward toward the convex side; 
